* GardaWorld makes cash offer of 190p/share for G4S (CSE:G4S)
* G4S rejected GardaWorld earlier proposal for same amount
* G4S shares up 5% at 198.9p (Adds G4S response)
By Aakash B and Yadarisa Shabong
Sept 30 (Reuters) - Security group G4S GFS.L on Wednesday rejected a cash offer by smaller Canadian rival GardaWorld that valued the British company at 2.97 billion pounds ($3.81 billion), weeks after it turned down a similar proposal.
G4S, one of the world's largest private security companies, had rejected GardaWorld's sweetened 190 pence per share proposal earlier in September, calling it "highly opportunistic." It also rejected two prior proposals in June for 145 pence per share and 153 pence per share each. said: "Shareholders are strongly advised to take absolutely no action in relation to the unattractive and opportunistic offer."
Shares in London-listed G4S were up 5% at 198.9 pence by 1125 GMT, above the 190 pence offer made by GardaWorld's subsidiary Fleming Capital Securities. GardaWorld made its offer for G4S public on Sept. 14, G4S shares are up 30%.
"The G4S Board has behaved in a cavalier way by rejecting our potential offer out of hand," GardaWorld's Chief Executive Stephan Cretier said.
"We look forward to meeting with investors to explain the challenges ahead and why this is a full and fair price," Cretier added.
The latest offer, which is for the same amount as the one made a few weeks ago, represents a premium of 0.5% to G4S' Tuesday's closing stock price. Analysts had likened the takeover approach as "the tiddler swallowing the whale".
GardaWorld's interest in G4S was made known last year, when it considered a cash offer for some or all of G4S, but by May had opted not pursue a deal. the past year G4S has had to overcome a series of setbacks, including the loss of a contract to run a Birmingham prison, and a decision by Norway's wealth fund not to invest in the company. sold off most of its cash-handling business in February to U.S. peer Brinks Co BCO.N . ($1 = 0.7790 pounds)