Buyout offer ups Quest shares

Quest Software, a maker of software to help companies manage cloud computer systems, rose above a new $25.50-a-share cash buyout offer from a strategic bidder that topped a previous agreement with Insight Venture Partners.

The shares increased 8.5% in New York in early trade, for the biggest gain since May 9, when Quest said it had proposals after reaching a deal to be bought by Insight for $23 a share. Through Wednesday, the stock had climbed 28% this year.

The company employs 3,900 worldwide and 220 people at its Citygate Business Park Mahon Point offices.