PHNOM PENH, Cambodia (CNN) -- Cambodian Premier Hun Sen has approved royal pardons for five prominent political figures under a deal to form a new government with rival Prince Norodom Ranariddh.

King Norodom Sihanouk said in a statement Friday that Hun Sen agreed to the amnesties for the five in exchange for Ranariddh's agreement to form a coalition.

The five, which include two members of the royal family, had been convicted of various security crimes.

The king said other differences between Hun Sen and Ranariddh, including which party would get the key post of National Assembly president remained unresolved.

"Hun Sen has the desire to make the concession to Prince Norodom Ranariddh and ask for pardons to be granted (to the five) ... on the other hand, Prince Norodom Ranariddh ... agrees to arrange a new coalition government," the king said.

Among the five are Prince Norodom Chakrapong, a son of the king's and half-brother of Ranariddh's, who was allegedly involved in a 1994 coup attempt. He was allowed to leave the country and later convicted.

Also to be pardoned under the deal is former Foreign Minister Prince Norodom Sirivudh, a half-brother of Sihanouk's, who was convicted in February 1996 in absentia of allegedly plotting to kill Hun Sen. He was allowed to leave the country before his conviction.

According to the constitution the king has the power to grant amnesties but he has said he will only issue pardons if the prime minister agrees.

Two of Ranariddh's top military men, General Nhiek Bun Chhay and General Serey Kosal, convicted in absentia of security crimes in March this year, will also be pardoned, the king said.

The two generals are based in opposition-controlled enclaves on the border with Thailand.

The fifth person to receive a pardon is a former interior minister and member of Hun Sen's party, General Sin Song, who was convicted of involvement in the same alleged coup plot that Chakrapong was said to have been involved in. He escaped from custody and fled to Thailand.

The king also said in his statement that the new coalition would be arranged "step by step."

Ranariddh arrived back in Phnom Penh from Thailand on Thursday for the first time since late September and said he was ready to form a coalition with his bitter rival, Hun Sen.

Hun Sen's ruling party did not win enough seats in the disputed July 26 vote to form a new government alone.

"My position is clearly that we will join a coalition government...FUNCINPEC will participate in a coalition government," Ranariddh told Reuters shortly after arriving back in Cambodia, referring to his FUNCINPEC political party.

Absent from the talks is Ranariddh's opposition ally Sam Rainsy whose party came in third in the election.

Ranariddh and former finance minister Sam Rainsy rejected Hun Sen's polls victory alleging his party won through fraud and intimidation.

Together they mounted weeks of protests against the vote and opposition supporters were killed in street clashes with police during the demonstrations in September.

Hun Sen has made it clear that he wants a coalition with Ranariddh's party alone without Sam Rainsy's party.

Ranariddh returned to meet Hun Sen after coming under intense pressure from his father and the international community, especially Cambodia's biggest aid donor Japan, to open talks on a government.

About 100 of the prince's supporters were executed by members of the security forces under Hun Sen after he ousted his then senior co-premier Ranariddh in a bloody coup in July last year.

Reuters contributed to this report.