How Can I Parse A String Before Any Operator Sign ?

using System;
using System.Linq;
using System.Collections.Generic;

namespace Sample {
    
   // Beware, no error handling have been considered!
   public static class MyExtensions {
        private static readonly IEnumerable<string> Delimiters = new[] { ">=", "<=", "!=", ">", "<", "=" };

        public static string GetVariable(this string expression) {
            if (Delimiters.Any(expression.Contains)) {
                var delimiter = Delimiters.Where(expression.Contains).First();
                return expression.Split(new[] { delimiter }, StringSplitOptions.RemoveEmptyEntries).First();
            }
            return null;
        }
    }

    class Program {
        static void Main(string[] args) {
            var input = new[]
                {
                    "EndMarket=100",
                    "EndMarket<200",
                    "EndMarket>300",
                    "EndMarket!=300"
                };

            foreach (var s in input) {
                Console.WriteLine("{0}: {1}", s, s.GetVariable());
            }
        }
    }
}

string textValue = EndMarket<=100;
string [] splitted_string = textValue.Split(new Char [] {'<', '>', '='});
foreach (string sp in splitted_string) {

       if (sp.Trim() != "")
         {
         //do something with sp (which returns you the first part i.e EndMarket or whatever you use in the textValue 
         }            
 }