(Adds analysts on possible deal extension, Conti spokesman, updates shares)
By Christiaan Hetzner
FRANKFURT, June 29 (Reuters) - Stock in automotive supplier Phoenix AG rose on Tuesday as investors bet a 227 million-euro ($276 million) takeover by rival Continental AG will go through despite last-minute worries.
Phoenix shares traded as high as 15.60 euros, a level last seen in 1999 and more than the 15 euros Continental is offering, even though the tyre maker said it would not sweeten its offer to win the 75 percent of Phoenix shares it needs for the deal.
The shares were up 2.7 percent at 15.52 euros at 1222 GMT.
The deadline for Phoenix shareholders to accept Continental's offer expired late on Monday. The company said on Monday that the deal was in acute danger of collapsing with "less than 70 percent" support.
A spokesman for Continental said the company still had no clarity about the number of shares tendered, but said that an announcement could be expected on Tuesday afternoon.
"It's a very reasonable price and I'd be surprised to see this deal not go through," said Heino Ruland, head of sales and research at Frankfurt brokerage Steubing.
"If the takeover were to fail, Phoenix shares would be trading for 11-12 euros, maximum 13," he added.
Some equity analysts have been telling their clients this week that Continental could still extend its offer -- but takeover lawyers agree with Continental saying that the legal deadline to change the offer elapsed on Friday.
Phoenix's biggest shareholders, Daun & Cie. and WestLB [WDLG.UL] have already tendered the 37 percent of the company they own.
Landesbank Baden-Wuerttemberg analyst Stilian Boiadjiev believed speculative investors were probably betting up to the last second that Continental would in fact up the bid price.
"Following the deal's announcement in March, we received phone calls from investors in London asking whether an improved bid might be offered," he said.
"Since a lot of funds were invested in the stock -- some of whom stocked up later as well and could be counted on to apply pressure to Continental management -- we thought the company would come back with a sweetened offer," Boiadjiev added.
"Continental has stood firm, however, and we are recommending clients to accept what is a very generous offer. We fully expect Continental to receive the necessary 75 percent acceptance rate," he said.