Bulgarian software developer Sirma Group Holding has extended the deadline for the subscription of its 39.57 million levs ($23 million/20.2 million euro) capital hike to February 15 from January 21, it said on Monday.The decision was approved by the board of directors of Sirma Group Holding, the company said in a filing to the Bulgarian Stock Exchange. It gave no reason for its decision.Sirma Group Holding said in November it is seeking to raise 39.57 million levs through a new share issue. The company is offering for subscription 39.57 million shares of 1 lev on par value each, equal to their sale price.Shareholders will receive one right for every Sirma Group Holding share they own. Each 1.5 rights entitle their holder to subscribe for one share from the new issue.The issue will be considered successful it at least 19.79 million shares are subscribed for and paid for.If the issue is fully subscribed, Sirma Group Holding will increase its capital to 98.93 million levs from 59.36 million levs.